#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>



int main() {

    int max = 0, num;

    for (int i = 0; i < 4; i++)

    {

        scanf("%d", &num);

        if (max <= num)

            max = num;

    }

    printf("%d", max);

    return 0;

}